[The detection of highly-transmissible genotypes of agent in clinical samples for prognosis of unfavorable course of tuberculosis.]

ABSTRACT

The bio-information search was carried out and the design of primers and TaqMan probes was developed to detect DNA of agent of tuberculosis subtypes CC1 and CC2-W148 of Beijing genotype and also Ural genotype in various clinical material (phlegm, spinal fluid, pleural fluid, etc.) using real-time polymerase chain reaction technique. The 180 clinical samples from 143 patients with tuberculosis of lungs were used to carry out an approval of sensitivity and specificity of the developed tests concerning studies at the genetic analyzer GeneXpert. The sensitivity of tests on CC1, CC2-W148 и Ural relating to polymerase chain reaction of analyzer Gene Expert made up to 91%, 106% and 81% correspondingly. In all cases, the specificity made up to 100%. In parallel studies the samples with DNA of СС2-W148 genotype were more often positive on mutation of resistance to Rifampicin-Rif (+) according the results of GeneXpert (χ² = 27,1; p < 0,01) related to other genotypes. At the same time, detection of СС2-W148 strain in patient was more often accompanied by discrepancy of results: GeneXpert - Rif (+) and resistance to Rifampicin in bacteriological study under ultimate validation of multiple medicinal resistance of tuberculosis (χ² = 5,1; p < 0,05). The analysis was applied to negative effect of combination of allele-336G of CD209 gene of patient with genotype of tuberculosis mycobacterium Beijing detected previously (Ogarkov et al., 2012). The significant prevalence was observed related to widespread medicinal resistance (χ² =4,3; p < 0,05) in patients with allele-336G of CD209 gene in combination with CC2-W148 clone in comparison with other combinations in patients. The obtained results testify a possibility of application of genetic typing of tuberculosis agent and patient for early diagnosis of development of various complications of tuberculosis at the stages of primary examination of primarily detected patients with tuberculosis.